Saturday, April 10, 2010

A predatory Velociraptor has been caught in the act of eating another larger plant-eating dinosaur.

Palaeontologists have uncovered fossil fragments of Velociraptor teeth alongside scarred bones of the large horned herbivore Protoceratops. The teeth of the predator match marks on the herbivore's bones, suggesting Velociraptorscavenged its carcass.

The discovery is further evidence that predatory dinosaurs both hunted and scavenged their plant-eating relatives. The find also helps validate another famous fossil discovery unearthed in 1971.

"This looks like scavengingas the animalwould be feeding on thehaunches and guts first,not the cheeks."

Fossil co-discoverer Dr David Hone

Known as the "fighting dinosaurs", that fossil shows a Velociraptor and Protoceratops apparently locked in combat, with both dinosaurs having died at the same time.

Evidence of feeding by theropod dinosaurs, such as Velociraptor or Tyrannosaurus rex, are scarce in the fossil record and the fighting dinosaurs is the most dramatic example known potentially illustrating such behavior.

Palaeontologists continue to debate the fossil and many still consider it possible that the two animals killed each other - the Velociraptor's raptor-like claw is preserved lodged in the throat region of the much larger Protoceratops, which appears at the same time to be biting down on the predatory dinosaur's right arm.

It is also possible that Velociraptor did not regularly eat Protoceratops. Instead, the fighting dinosaurs could represent a chance encounter between the two species that escalated into a fight.

However, the new fossil discovery, published in the journal Palaeogeography, Palaeoclimatology, Palaeoecology, suggests that is less likely. It provides further evidence that Velociraptor did regularly eat Protoceratops, either by scavenging those that had already died or by actively hunting them.

Dr David Hone of the Chinese Academy of Sciences in Beijing made the new discovery in Upper Cretaceous deposits at Bayan Mandahu, in Inner Mongolia, China.

Colleague Dr Jonah Choiniere originally found a mass of badly eroded Protoceratops bones. Among them lay two Velociraptor-like teeth. Together with Dr Hone and colleagues Dr Corwin Sullivan and Dr Mike Pittman, Dr Choiniere analysed the fossils for bite marks.

The team found the Protoceratops bones were scarred in this way, and the bite marks matched the teeth found alongside. The Velociraptor found at the site likely scavenged this particular Protoceratops, rather than hunted it.

"The marks were on and around bits of the jaw," Dr Hone said.

"Protoceratops probably weighed many times what a Velociraptor did, with lots of muscle to eat. Why scrape away at the jaws, where there's obviously not much muscle, so heavily that you scratch the bone and lose teeth unless there was not much else there.

"In short, this looks like scavenging as the animal would be feeding on the haunches and guts first, not the cheeks.

DINO DISCOVERIES

Dr Hone and colleagues earlier this month announced the discovery of a close relative of the swift, predatory dinosaur Velociraptor.

Last week they also revealed a fossil "roadrunner dinosaur", one of the smallest and most agile dinosaurs yet known.

Last year, the oldest dinosaur burrows were found.

"The fighting dinosaurs suggests predation. Combine the two and we have good evidence for both behaviors," says Dr Hone.

"Animals like Velociraptor were probably feeding on animals like Protoceratops regularly, probably including both predation and scavenging."

That is in line with the behavior of many modern predators, as almost all living carnivores such as lions and jackals do both.

Regular and Featured Topics

360 Hot Topics - News of the strange, bizarre, unknown or just plain weird with links for further reading. Subjects include every topic on our masthead.

360 In-Depth - Our award-winning series of reports providing a deeper look into the stories behind the headlines, offering analysis and educated opinion.

360 News & Comment: An Op/Ed feature focusing on a news topic that begs an opinion.

360 News Briefs - An early morning news feature profiling the latest news. Great with coffee!

360 OverNight - A night-time feature while most of the western hemisphere is sleeping. Great for night owls and our friends on the other side of the world.

360 Perspective/360 Analysis - For stories too short to be an In-Depth feature; an exposé that reports hourly, daily or weekly on news items not covered or expanded on by the media.

360 Sunday - An all-day Sunday Feature including 360 Sunday Extra, People and Stories of Faith and Hope, selected religious and spiritual news from around the world, plus the latest news and headlines.

360 Vent - The return of a site favorite - no one person, group or entity escapes our venting. Funny but not always pleasant, but then again, sometimes the truth can be painful.

Bits and Pieces - A news summary of regional and world interest.

Flashback - A fond glance at the music and television of the 70s, 80s, 90s & early millenium years, with special features going back to the 30s and 40s.

Left-Wing Watch - A breakdown of active socialism in America, Obama and his supporters, the people behind the scenes, the hows and whys of their policies that derail America.

Notes From All Over - A news break down that features several stories of interest: Georgia, US & World

The Quickening - A series of reports based on the belief that events in this country and around the world seem to be accelerating toward a point where great change is going to occur; events that will dramatically and radically alter life as we know it today.

The World Tonight - A world news round-up at the end of selected weekdays.

This American Life - A synopsis from across the nation on the lighter side of the news.